Panic exit door latch



3, 1959 H. w. JACKSON PANIC EXIT DOOR LATCH Filed Dec. 17, 1956 INVENTOE BY jlzrve United States Patent PANIC EXIT noon LATCH Harvey W. Jackson, Grosse Pointe Farms, Mich., a ssignor to Trans Continental Industries, Inc., Detroit, Mich., a corporation of Michigan Application December 17, 1956, Serial No. 628,741

4 Claims. (Cl. 70-92) This invention relates to door locks and latches and, in particular, to so-called panic exit door locks and latches.

Doors for public buildings and the like are customarily equipped with so-called panic exit latches having a latch bolt which is retracted automatically when a person leans or presses against a horizontal panic bar mounted on levers attached to the inner side of the door. This device prevents persons from being trapped inside a burning building, and even the weight of a person falling against the panic bar will unlatch the door from the inside and cause it to swing open to the outside. Modern doors, however, for artistic reasons have often very narrow stiles or border frames with the center occupied by a glass or plastic pane or panel which is nearly the size of the entire door. Difiiculty has been encountered in equipping such doors with conventional panic exit latches because of the fact that the available bolt-operating mechanisms were not sufliciently compact to fit into the particular size and shape of the space available in a modern narrow-framed door, such as within a correspondingly narrow casing attached to the door.

Accordingly, one object of the present invention is to provide a panic exit latch having bolt-operating mechanism which is so compact as to be accommodated within a very narrow space, such as within a narrow casing attached to the narrow stile of the door, yet which will operate efficiently and dependably in response to pressure upon the horizontal panic bar operatively connected thereto and mounted on the casing.

Another object is to provide a panic exit latch of the foregoing character in which the latch bolt is actuated by unusually simple mechanism requiring few working parts and occupying a minimum of space, either to house the parts themselves while in a static condition or to give them sufficient operating room for their motion during operation.

Another object is to provide a panic exit latch of the foregoing character in which the latch bolt and its operating mechanism are also adapted to be released from the outer side of the door by a key inserted in a conventional pin tumbler cylinder lock mounted in the door.

Other objects and advantages of the invention will become apparent during the course of the following description of the accompanying drawings, wherein:

Figure 1 is a vertical section through a panic exit latch in its latched position, according to one form of the invention, taken along the line 11 in Figure 2, as exemplified by a so-called surface applied latch;

Figure 2 is a vertical section in a plane at right angles to that of Figure 1, taken along the line 2-2 in Figure 1;

Figure 3 is a horizontal section taken along the line 3-3 in Figure l; and

Figure 4 is a fragmentary front elevation of the lower portion of the cam slide of the panic exit latch shown in Figures 1 to 3 inclusive.

Referring to the drawings in detail, Figure 1 shows a "ice surface-applied panic exit latch, generally designated 10, as mounted upon the inner surface 12 of the hollow metal outer stile 14 of a door, generally designated 16, having a pane or panel 18, preferably of glass, plastic or other transparent or translucent material. The details of the door 16 are beyond the scope of the present invention as the invention may be applied to any conventional door. While the invention has been shown as applied, for purposes of illustration, to a metal door with a glass central panel, it may obviously also be applied to a door with a border frame of wood or other material, or even to a door with opaque central panels. The door stile 14 consists of two mutually interengaging elongated hollow extruded members 20 and 22 respectively (Figure 3), the former having a pane or panel-receiving rabbet 24 adapted to receive the edge of the pane or panel 18. The pane or panel 18 is held in position by the edge 26 of the retaining member 22 bearing against the pane or panel 18 and in turn urging the latter against the edge 28 of the rabbet 24. In order to hold the members 20 and 22 together, the member 29 is provided with a dovetail groove 30 located immediately adjacent the rabbet 24 and slidably engaged. by the spaced dovetail ribs 32 and 34 on the inner side 36 of the hollow extruded retaining member 22.

The extruded member 20 of the stile 1.4 has an inner wall 38 to which the panic exit latch 10 is secured as by the screws 40 extending through the top and bottom flanges 42 of a hollow latch casing 44. The latter is rabbeted or recessed as at 46 adjacent the flanges 42 to receive the correspondingly stepped upper and lower ends 48 of a generally plate-shaped latch base 50. The hollow casing 44 is provided with a hollow extension 52 near its lower end, terminating in spaced parallel substanlially vertical ears 54 (only one of which is shown), which are drilled to receive a pivot pin 56 upon which the central portion of a panic bar supporting lever 58 is pivotally mounted. The panic bar supporting lever 58 has a wedge-shaped internal arm 60 and a downwardly-extending external arm 62 terminating in a horizontallydrilled boss 64 having a horizontal bore 66 in which is mounted the outer end of a horizontal panic bar 68. The panic bar 68, the major portion of which is omitted, is of conventional construction and its details are wellknown to those engaged in the building hardware industry and business. The panic bar 68 extends across the space occupied by the pane or panel 18 and is supported at its opposite end by a pivoted arm (not shown) similar to the external arm 62 of the supporting lever 58 and similarly mounted upon the inner vertical stile of the door 16 upon a pivot coaxial with the pivot pin 56.

The casing extension 52 below the supporting ears 54 for the pivot pin 56 is provided with a threaded vertical bore 70 and threaded counterbore 72, the former of which opens into the interior of the casing 44 immediately below the approximate midportion of the internal arm 60 of the outer panic bar supporting lever 58. Threaded into the inner or upper bore 70 is a headless set screw 74, the nose 76 of which is adapted to engage the approximate midportion of the internal supporting lever arm 60 on its lower edge or under side. A tubular retaining nut 78 is threaded into the counterbore 72 in order to act as a stop so as to limit the withdrawal of the set screw 74 and thus prevent its loss. The tubular retaining nut 78 has a central opening 80 sufficiently large for the free insertion and rotation of the nose of an operating key or wrench (not shown) into the socket 82 in the lower end of the set screw 74.

Reciprocably mounted in the casing 44 with its face 84 slidably engaging the inner surface of the outer wall 86 of the casing 44 is a generally plate-shaped cam slide,

' the lower ends of compression springs 94 (Figure 1), the

upper ends of which are mounted in similar sockets 96 in the lower sides of laterally-spaced bosses 98 integral with the base 50 and projecting approximately horizontally toward the cam slide 88. The latter immediately above the spring abutment 90 is provided with a rectangular opening 100 through which projects the nose 102 of the internal arm 60 of the panic exit bar supporting lever 58. In this manner, the cam slide 88 is urged downwardly by the springs 94 so that the upper edge 104 of the opening 100 bears against the upper edge 106 of the nose portion 102 of the lever 58.

Disposed adjacent one edge of the cam slide 88 (Figure 4) and projecting therefrom toward the base 50 immediately above the upper edge 104 of the opening 100 is a cam 108 in the form of a boss having an inclined cam edge 110 engageable with the arcuate follower surface 112 on the lower arm 114 of a latch bolt-operating lever 116 having an upper arm 118 provided with an elongated slot 120. The latch bolt-operating lever 116 is bored as at 122 to receive the inner end of a pivot pin 124, the outerend of which is seated in a bore 126 in the lower portion 128 of a boss 130 projecting from the base 50 toward the outer wall 86 of the casing 44. The boss '130 is provided with a horizontal latch bolt guide groove or guideway 132 in which a latch bolt 134 with a rounded inner surface 137 is reciprocably mounted.

The latch bolt 134 passes through a rectangular opening 135 in the casing 44 and is drilled as at 136 near its rearward end to receive a pin 138 which engages the elongated slot 120 in the lever 116. Above and below the pin 138, the rearward end of the bolt 134 is provided with sockets 140 (Figure 2) adapted to receive the forward ends of compression springs 142, the rearward ends of which engage sockets 144 in the boss 130 at the rearward end of the guide groove 132. In this manner, the springs 142 constantly urge the bolt 134 forward (to the left in Figure 2) toward its latching position.

In order to actuate the bolt-operating mechanism from the outside of the building and enable an authorized person to enter the building through the door outside of business hours, the lower arm 114 of the latch bolt operating lever 116 is drilled at 150 to receive a transverse pin 152 which is engaged by the upper end of a crank or rotary camming member 154 having a cup-shaped hub 156 which is rotatably mounted in a hole 158 in the baseplate 50 (Figure 1). The hub 156 in its end wall is provided with an elongated slot 160 adapted to be engaged by the rotary output member 162 of correspondingly elongated cross-section connected to the rotary tumbler cylinder 164 of a conventional pin tumbler cylinder lock, generally designated 166, the flanged cylindrical casing 168 of which is threaded into a hole 170 in the outer wall 172 of the door stile 14. The pin tumbler cylinder 164 at its outer end is provided with the usual key opening in which a conventional key (not shown) is inserted and, if of the proper configuration, is permitted to be rotated by displacing the tumbler pins which otherwise prevent such rotation, thereby rotating the output member 162, as explained below in connection with the operation of the invention.

In the operation of the invention, let it be assumed that the building equipped with the door 16 has been closed for the night or a Sunday or holiday, and that for this purpose the parts are in the positions shown in Figures 1 to 3 inclusive, with the latch bolt 134 projected into its keeper in the door frame (not shown) and with the set screw 74 in its lowered position (Figure 1) to permit this. The door 16 is now latched by the projected bolt 134 so as to prevent ingress. During the night or during the daytime of a Sunday or holiday, a person inside the building may unlatch the door merely by pushing horizontally against thelpanic bar 68. This action swings the panic bar supporting lever 58 clockwise around its pivot pin 56 (Figure 1), causing the internal arm 60 thereof to swing upward and consequently to move the cam slide 88 and its cam 108 upward. This action causes the inclined cam surface 110 to engage the arcuate lower end portion 112 of the lower arm 114 of the latch bolt operating lever 116, swinging the latter in a clockwise direction (Figure 2) so that its slotted upper arm 118 moves rearwardly to retract the latch bolt 134 by the engagement of the walls of the slot 120 with the pin 138.

The retraction of the latch bolt 134 from its keeper unlatches the door 16 and permits the person pushing against the panic bar 68 to swing the door open toward the outside of the building. In this manner, a person can unlatch the door 16 and leave the building at times outside of business hours, either under normal conditions or in case of fire or other emergency, merely by leaning against the panic bar 68. When the door 16 swings backward under the influence of its door check (not shown), the rounded rearward surface 137 of the bolt 134 engages the edge of the keeper with a cam action which pushes the bolt 134 rearwardly into the casing 44 until the front end of the bolt 134 passes the front edge of the keeper, whereupon the springs 142 again project the bolt 134 into its keeper, relocking the door 16 behind the departing person.

When the custodian of the building or other person opens the building at the beginning of business hours, he inserts a key or wrench through the bore of the tubular set screw 78 into the socket 82 of the set screw 74 and rotates the key or wrench to thread the set screw 74 upward in its threaded bore 70 (Figure l), causing its nose 76 to push against the lower edge of the internal arm 60 of the panic bar supporting lever 58 and push it upward, at the same time moving the cam slide 88 upward by the contact of the nose portion 106 with the upper edge 104 of the opening 100. This action swings the latch bolt operating lever 116 clockwise by the action of the inclined cam surface 110 against the arcuate lower end portion 112 thereof, retracting the latch bolt 134 into the casing 4 and holding it there during business hours. The door 16 can be freely opened from the outside or inside to permit free ingress and egress. At the close of business hours, the custodian again applies the wrench to the socket 82 of the set screw 74 and rotates it counterclockwise to move the set screw 74 downward toward the tubular stop screw 78. This action permits the supporting lever 58 to be swung counterclockwise and the panic bar 68 to be move-d outward away from the door 16 by the action of the coil springs 94 against the abutment shelf 92 at the lower end of the cam slide 88, the upper edge 104 of the opening therein engaging the nose portion 106 of the supporting lever 58 and pushing the nose portion 106 downward.

To release the latch bolt 134 and enter the building from the outside by means of a suitable key, an authorized person having such a key inserts it in the opening at the front of the rotary tumbler cylinder 164, the jagged edge of the key displacing the locking tumblers in so doing and releasing the tumbler cylinder 164 for rotation. The operator then turns the key in the usual way, rotating the tumbler cylinder 164 and its output member 162, consequently swinging the crank or rotary camming member 154 in a clockwise direction, looking from the outside of the door (to the left of Figure 1) or counterclockwise as viewed in Figure 2. The consequent engagement of the crank or rotary camming member 154 with the pin 152 on the lower arm 114 of the bolt operating lever 116 swings the latter in the same direction that it swings when engaged by the edge of the can; 103 when the slide 88 is moved upward in response to pushing inward upon the panic bar 68. This motion is transmitted to the bolt 134 through the pin and slot connection 138, 120, retracting the bolt 134.

What I claim is:

1. A panic eXit door latch adapted to be operated selectively by a conventional panic bar and by the rotary output member of a conventional key-released lock, said latch comprising an elongated hollow casing, a panic bar supporting lever pivotally mounted on said casing and having an operating portion projecting into the interior of said casing, a slide movably mounted in said casing for reciprocation longitudinally of said casing and in operative engagement with said operating portion, a latch bolt movably mounted in said casing for reciprocation laterally of said casing, a cam clement mounted on and reciprocable with said slide, a motion-transmitting lever pivotally mounted in said casing in operative engagement with said cam element and operatively engaging said latch bolt and responsive to the longitudinal motion of said slide for laterally moving said latch bolt, and a rotary camming member rotatably mounted in said casing in leverswinging engagement with said motion-transmitting lever and adapted to be operatively connected to the rotary output member of the lock, said motion-transmitting lever being also responsive to the rotation of said rotary camming member for laterally moving said latch bolt.

2. A panic exit door latch adapted to be operated selectively by a conventional panic bar and by the rotary output member of a conventional key-released lock, said latch comprising an elongated hollow casing, a panic bar supporting lever pivotally mounted on said casing and having an operating portion projecting into the interior of said casing, a slide movably mounted in said casing for reciprocation longitudinally of said casing and in operative engagement with said operating portion, a latch bolt movably mounted in said casing for reciprocation laterally of said casing, a cam element mounted on and reciprocable with said slide, a motion-transmitting lever pivotally mounted in said casing in operative engagement with said cam element and having a pin-and-slot connection with said latch bolt and responsive to the longitudinal motion of said slide for laterally moving said latch bolt, and a rotary camming member rotatably mounted in said casing in lever-swinging engagement with said motion-transmitting lever and adapted to be operatively connected to the rotary output member of the lock, said motion-transmitting lever being also responsive to the rotation of said rotary camming member for laterally moving said latch bolt.

3. A panic exit door latch adapted to be operated selectively by a conventional panic bar and by the rotary output member of a conventional key-released lock, said latch comprising an elongated hollow casing, a panic bar supporting lever pivotally mounted on said casing and having an operating portion projecting into the interior of said casing, a slide movably mounted in said casing for reciprocation longitudinally of said casing and in operative engagement with said operating portion, a latch bolt movably mounted in said casing for reciprocation laterally of said casing, a cam element mounted on and reciprocable with said slide, a motion-transmitting lever pivotally mounted in said casing having a cam follower portion disposed in contacting engagement with said cam element and operatively engaging said latch bolt and responsive to the longitudinal motion of said slide for laterally moving said latch bolt, and a rotary camming member rotatably mounted in said casing in lever-swinging engagement with said motion-transmitting lever and adapted to be operatively connected to the rotary output member of the lock, said motion-transmitting lever being also responsive to the rotation of said rotary camrning member for laterally moving said latch bolt.

4. A panic exit door latch adapted to be operated selectively by a conventional panic bar and by the rotary output member of a conventional key-released lock, said latch comprising an elongated hollow casing, a panic bar supporting lever pivotally mounted on said casing and having an operating portion projecting into the interior of said casing, a slide movably mounted in said casing for reciprocation longitudinally of said casing and in operative engagement with said operating portion, a latch bolt movably mounted in said casing for reciprocation laterally of said casing, a cam element mounted on and reciprocable with said slide and having a cam surface thereon inclined relatively to the axis of reciprocation of said slide, a motion-transmitting lever pivotally mounted in said casing and having a cam follower portion disposed in contacting engagement with said cam surface, said motion-transmitting lever operatively engaging said latch bolt and responsive to the longitudinal motion of said slide for laterally moving said latch bolt, and a rotary camming member rotatably mounted in said casing in lever-swinging engagement with said motion-transmitting lever and adapted to be operatively connected to the rotary output member of the lock, said motion-transmitting lever being also responsive to the rotation of said rotary camming member for laterally moving said latch bolt.

References Cited in the file of this patent UNITED STATES PATENTS 917,685 Voight Apr. 6, 1909 920,507 Voight May 4, 1909 1,146,366 Stewart July 13, 1915 1,701,099 Clark Feb. 5, 1929 1,756,667 Soemer Apr. 29, 1930 1,815,584 Prinzler July 21, 1931 2,724,606 ,Wartian Nov. 22, 1955 

